JPH0143342Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field This invention is a quick-filling master cylinder for vehicles,
In particular, the cylinder body is provided with a stepped cylinder hole consisting of a small diameter part at the front and a large diameter part at the rear, and this cylinder hole has a small diameter piston part and a large diameter piston part corresponding to the small diameter part and the large diameter part, respectively. The pistons are slid together, and at a predetermined retracted position of the piston, a relief port opens into a hydraulic chamber formed in front of the small diameter piston section, and a relief port opens into a replenishment oil chamber formed between the small diameter piston section and the large diameter piston section. A supply port is connected to the oil tank via an oil passage, and a valve device is interposed in the oil passage, and the valve device opens when the pressure in the supply oil chamber rises to a predetermined value or more. a pressure-responsive valve; a one-way valve that allows oil to flow only through the one-way valve from the oil tank to the replenishment oil chamber; and a one-way valve that bypasses the pressure-responsive valve and the one-way valve to connect the oil tank to the relief port. This invention relates to an improvement in a device equipped with a bypass having a large flow resistance communicating between the two.

(2) Prior art Conventionally, this type of master cylinder has an oil tank in the upper part of the cylinder body, and a valve chamber in the side part of the cylinder body and in the lower part of the oil tank, and the valve chamber has a one-way valve and a pressure valve. A type equipped with a response valve is known.

(3) Problems to be solved by the invention However, in the master cylinder, while maintaining the width of the conventional oil tank (the length in the direction orthogonal to the axial direction of the cylinder body), the cylinder body and the valve chamber are If you try to narrow the width of the oil tank, part of the valve chamber will protrude from the bottom of the oil tank to the side, and at the same time, the height of the oil tank will increase in order to secure the specified amount of oil. On the other hand, if an attempt is made to lower the height of the oil tank, the width of the oil tank will become wider than before, resulting in a problem.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide the quick-filling master cylinder described above, in which the height and width of the oil tank can be reduced.

B. Structure of the invention (1) Means for solving the problems The invention provides an arrangement in which the oil tank is communicated with an upper oil chamber located at the upper part of the cylinder body, and the oil tank is connected to the upper oil chamber located at the upper part of the cylinder body. A small diameter cylinder extending in the axial direction of the main body is integrally provided at the lower part of the cylinder body, and the oil passage is formed in the small diameter cylinder, and the oil passage is formed in the oil passage. A valve chamber for accommodating a valve device is provided, and the one-way valve includes a valve seat formed on an inner end surface of the valve chamber, a hollow cylindrical valve body facing the valve seat, and a hollow cylindrical valve body formed in the valve seat. The valve spring biases the valve seat toward the valve seat, and the pressure-responsive valve is incorporated into the hollow cylindrical valve body.

(2) Effect When the piston moves forward and the relief port is closed, hydraulic pressure is generated in the hydraulic chamber, and the hydraulic pressure is transmitted to the specified equipment. In addition, since the volume of the supply oil chamber is reduced, the oil discharged from the oil chamber hardly returns to the oil tank due to the large flow resistance of the bypass and the closure of the one-way valve, and is quickly filled into the hydraulic chamber. Ru.
When the oil pressure in the replenishment oil chamber rises above the prescribed opening pressure of the pressure-responsive valve, the pressure-responsive valve opens.

When the oil in the valve chamber is replenished to the hydraulic chamber through the supply port and the replenishment oil chamber as the pressure in the hydraulic chamber decreases when the piston retreats, the one-way valve opens and oil is replenished from the oil tank to the valve chamber.

Hydraulic operation of each of the above-mentioned parts can be carried out for a long time without any trouble because a sufficient amount of oil is ensured by the upper oil chamber and the side oil chamber that constitute the oil tank.

(3) Embodiment The drawing shows an embodiment in which the present invention is applied to a brake master cylinder for a motorcycle.
In the figure, a quick-filling master cylinder M is fixed to a steering handlebar 1 of a motorcycle via a bracket 2 that is integrated with a cylinder body 6 thereof. A brake lever 3 is pivotally mounted to the bracket 2 via a support shaft 5.

As shown in FIG. 2, the cylinder body 6 extends in the left-right direction of the vehicle body, and a piston 8 is slidably fitted into the cylinder hole 7 thereof. The piston 8 has a small diameter piston part 8 ₁ and a large diameter piston part 8 ₂ arranged in front and behind, and the cylinder hole 7 also has a small diameter part 7 ₁ and a large diameter part 7 ₂ corresponding to these piston parts 8 ₁ and 8 ₂ . It is formed in steps so that it can be held.

A hydraulic chamber 9 is defined between the front end wall of the small diameter portion 7 ₁ and the small diameter piston portion 8 ₁ , and the output port 1 on the front end wall
0 is connected to a brake hydraulic circuit (not shown).
Further, a replenishment oil chamber 11 is defined between the small diameter and large diameter piston sections 8 ₁ and 8 ₂ , and an oil hole that communicates the oil chamber 11 with the back surface of an elastic piston cup 12 attached to the front end of the small diameter piston section 8 ₁ . 13 is formed on the small diameter piston portion 8 ₁ .

A return spring 14 that urges the piston 8 in the backward direction is compressed in the hydraulic chamber 9, and the backward limit of the piston 8 is such that the back surface of the large diameter piston portion ₈₂ is locked to the inner wall of the large diameter portion ₇₂ . It is regulated by coming into contact with the stop ring 15.

As clearly shown in FIG. 3, an oil tank 16 is integrally provided in the cylinder body 6. The oil tank 16 includes an upper oil chamber 16 ₁ located at the upper part of the cylinder body 6;
The side oil chamber 16 ₂ communicates with the oil chamber 16 1 and is located on the side of the cylinder body 6 (in the illustrated example, on the rear side in _{the longitudinal direction of the vehicle body), and both oil chambers 16 1 ,} 16
₂ ensures a predetermined amount of oil. In addition, the height of the oil tank 16 is lowered by the same capacity as the side oil chamber ₁₆₂ ,
Or you can narrow the width. On the other hand, by reducing the capacity of the oil tank 16 in the height and width directions by the same amount, the height and width of the oil tank 16 can be reduced.

Further, a small diameter cylinder 17 extending in the axial direction of the main body 6 is integrally connected to the lower part of the cylinder body 6, and an oil passage 18 extends in the axial direction of the small diameter cylinder 17.
is formed. The front end side of the oil passage 18 communicates with the bottom of the side oil chamber ₁₆₂ via a communication passage 19, and the rear end side of the oil passage 18 is a relief port when the piston 8 is located at a predetermined retraction limit. Hydraulic chamber 9 and supply oil chamber 1 via 20 and supply port 21
1, respectively.

A long cylindrical valve chamber 22 is formed in the oil passage 18, and the relief port 20 and supply port 21 are opened in the valve chamber 22.

A valve device 23 that controls communication between the oil tank 16 and the replenishment oil chamber 11 is provided within the valve chamber 22 .

As clearly shown in FIGS. 4 and 5, this valve device 23 includes a one-way valve 24 that allows oil to flow only in one direction from the oil tank 16 to the replenishment oil chamber 11, and the one-way valve 24.
a pressure-responsive valve 25 that is incorporated in the replenishment oil chamber 11 and opens when the pressure in the replenishment oil chamber 11 rises to a predetermined value or more;
A bypass 26 with a large flow resistance is provided which bypasses both the valves 24 and 25 and communicates between the oil tank 16 and the relief port 20.

The one-way valve 24 has a valve seat 27 formed on an inner end surface of the valve chamber 22 that is located on the communication side with the oil tank 16.
, a hollow cylindrical valve body 28 facing the valve seat 27, and a valve spring 2 that urges the hollow cylindrical valve body 28 toward the valve seat 27.
It consists of 9. The hollow cylindrical valve body 28 is the valve seat 1
It consists of a spherical part 28a located on the 7 side and rotatably and slidably fitted into the valve chamber 22, and a cylindrical part 28b connected to the spherical part 28a and having a smaller diameter than the spherical part 28a. A stepped portion 30 is formed on the end surface of the cylindrical portion 28b, and the valve spring 29 is compressed between the stepped portion 30 and the inner end wall of the valve chamber 22. Normally, the resilient force of the valve spring 29 pushes the spherical portion 28a. is seated on the valve seat 27 and the oil tank 16 is opened.
is shut off from the supply oil chamber 11. Spherical part 2
8a is formed with four cutout-like communication passages 31 that communicate the valve seat side space a and the cylindrical part side space b in the valve chamber 2, and when the spherical part 28a is separated from the valve seat 27, the oil passage 18 is formed. The oil in the upstream part of the valve chamber 22 flows into the cylindrical part side space b through each communication passage 31.

A valve seat member 32 is attached to the opening of the cylindrical portion 28b.

The pressure-responsive valve 25 has a valve seat 33 formed on the inner end surface of the valve seat member 32, a spherical valve body 34 facing the valve seat 33, and a gap between the spherical valve body 34 and a stepped portion 35 in the spherical portion 28a. The valve spring 36 is compressed and urges the spherical valve body 34 toward the valve seat 33. Normally, the resilient force of the valve spring 36 pushes the spherical valve body 34 toward the valve seat 33.
The replenishing oil chamber 11 is isolated from the oil tank 16 by being seated on the oil tank 16.

The bypass 26 is composed of a space b on the cylindrical part side of the valve chamber 25, each communication passage 31, a space a on the valve seat side of the valve chamber 22, and a narrow groove 37 formed in the distal end surface of the spherical part 34. is always connected to the oil passage 18 and valve chamber 22.
and the valve seat side space a.

Next, the operation of this embodiment will be explained. When the brake pedal is operated to move the piston 8 forward from the illustrated retracted position, the piston 8 is moved forward by the return spring 1.
4, and after the piston cup 12 closes the relief port 20, hydraulic pressure is generated in the hydraulic chamber 9 according to the amount of advance of the piston 8, and this hydraulic pressure is output from the output port 10 to drive the corresponding wheel. Brakes can be activated.

During this time, especially the large diameter piston portion 8 ₂ of the piston 8
As the oil chamber 11 moves forward, the volume of the replenishing oil chamber 11 is reduced, so that the oil discharged from the oil chamber 11 flows through the narrow groove 37.
Due to the large flow resistance of the one-way valve 24 and the reliable sealing performance due to the spherical part 28a of the one-way valve 24 being seated on the valve seat 27 with a spherical surface, the oil hardly returns to the oil tank 16 side and passes through the oil hole 13. piston cup 1
The outer periphery of 2 is forced into the hydraulic chamber 9 while being bent forward. In this way, the hydraulic chamber 9 is rapidly filled with pressure oil, and as a result, output hydraulic pressure is generated at the output port 10 at an early stage, play in the wheel brakes is quickly removed, and these can be operated without time delay. can.

When the hydraulic pressure in the replenishing oil chamber 11 rises above the prescribed opening pressure of the pressure-responsive valve 25 due to the pressure increase in the hydraulic chamber 9, the spherical valve body 34 is moved toward the left in FIGS. 2 and 4 against the force of the valve spring 36. In order to open the pressure-responsive valve 24, the oil discharged from the supply port 21 of the replenishment oil chamber 11 is returned to the oil tank 16 from the pressure-responsive valve 25 through the upstream side of the oil passage 18. As a result, an excessive pressure rise in the replenishment oil chamber 11 is suppressed, so that the forward movement of the piston 8 is not hindered.

When the operating force from the brake pedal is released, each piston 8 is returned to its predetermined retraction limit by the return force of the return spring 14, and in the return process, the pressure in the hydraulic chamber 9 is reduced, and the outer circumference of the piston cup 12 is moved forward and backward. Due to the pressure difference, it bends forward and creates a gap between it and the inner surface of the cylinder hole 7, and as a result, the oil in the cylindrical side space b of the valve chamber 22 flows into the supply port 21 and the replenishment oil chamber 11.
The oil in the oil tank 16 is supplied to the hydraulic chamber 9 through the oil hole 13, and the oil in the oil tank 16 is supplied by moving the hollow cylindrical valve body 28 to the right in FIGS. 2 and 4 against the force of the valve spring 29. In order to open the directional valve 24, the oil flows from the upstream side of the oil passage 18 to the cylindrical side space b of the valve chamber 22.
efficiently flow into the country. In this case, since the spherical portion 28a of the one-way valve 24 is in line contact with the inner peripheral surface of the valve chamber 22, the sliding resistance of the hollow cylindrical valve body 28 is small, and the operation of the valve body 28 is smooth and stable. It will be held in

When the piston 8 returns to the predetermined retracted position, the relief port 20 opens to the hydraulic chamber 9, and the excess supply in the hydraulic chamber 9 is discharged to the oil tank 16 through the relief port 20 and the bypass 26 (Fig. 4). (see arrow).

Hollow cylindrical valve body 2 during hydraulic operation of each of the above parts
Even if the valve 8 is tilted as shown by the chain line in Figure 4, the one-way valve 2
In No. 4, the spherical portion 28a is seated on the valve seat 27 with a spherical surface, so that the spherical portion 28a and the valve seat 2
7 is reliably sealed, and the inclination of the hollow cylindrical valve body 28 has no effect on the operation of the pressure-responsive valve 25, so that the operation of the pressure-responsive valve 25 is always smooth and stable. can be done.

Moreover, the hydraulic operation of each of the above-mentioned parts can be carried out for a long time without any trouble because a sufficient amount of oil is ensured by the upper oil chamber 16 ₁ and the side oil chamber 16 ₂ that constitute the oil tank 16.

Note that the narrow groove 37 of the bypass 26 can be replaced with an orifice passing through the peripheral wall of the cylindrical portion 28b of the hollow cylindrical valve body 28.

C. Effects of the invention According to the invention, the oil tank is constituted by an upper oil chamber located at the top of the cylinder body, and a side oil chamber communicating with the upper oil chamber and located at the side of the cylinder body. The same amount of oil as in the conventional oil chamber can be secured in both oil chambers, and the height or width of the oil tank can be reduced by the same capacity as the side oil chamber. Furthermore, by reducing the capacity of the oil tank in the height and width directions by the same amount as above, the height and width of the oil tank can be reduced.

Furthermore, an oil passage is formed in a small cylinder integrally provided in the lower part of the cylinder body so as to extend in the axial direction of the body, a valve chamber for accommodating a valve device is provided in the oil passage, and the valve chamber is provided with a valve chamber for accommodating a valve device. Since the hollow cylindrical valve body of the one-way valve is accommodated in the cylinder body, and the pressure-responsive valve is built into the hollow cylindrical valve body, the dead space below the cylinder body can be effectively utilized to make the valve device compact. I can do it.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall plan view, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIG.
The drawings are a cross-sectional view taken along the line shown in FIG. 2, FIG. 4 is an enlarged cross-sectional view around the valve device, and FIG. 5 is an end view of the hollow cylindrical valve body viewed from the direction of the arrow in FIG. 6... Cylinder body, 7... Cylinder hole, 7 ₁ ,
7 ₂ ... Small, large diameter section, 9 ... Hydraulic chamber, 11 ... Supply oil chamber, 16 ... Oil tank, 16 ₁ , 16 ₂ ... Upper, side oil chamber, 17 ... Small diameter cylinder, 18 ... Oil passage, 20... Relief port, 21... Supply port, 22... Valve chamber, 23... Valve device, 24...
... One-way valve, 25 ... Pressure-responsive valve, 26 ... Bypass, 27 ... Valve seat, 28 ... Hollow cylindrical valve body, 2
9...Valve spring.

Claims (1)

[Scope of utility model registration request] The cylinder body is provided with a stepped cylinder hole consisting of a small diameter portion at the front and a large diameter portion at the rear, and a piston having a small diameter piston portion and a large diameter piston portion corresponding to the small diameter portion and the large diameter portion, respectively, is provided in the cylinder hole. At a predetermined retracted position of the piston, a relief port opens into a hydraulic chamber formed in front of the small diameter piston part and a replenishment oil chamber formed between the small diameter piston part and the large diameter piston part. The supply port communicates with the oil tank via an oil passage, and a valve device is interposed in the oil passage, and the valve device has a pressure that opens when the pressure in the supply oil chamber rises to a predetermined value or more. a response valve, a one-way valve that allows oil to flow only in one direction from the oil tank to the replenishment oil chamber, and a space between the oil tank and the relief port by bypassing the pressure-response valve and the one-way valve. In a quick-filling master cylinder for a vehicle, the oil tank is connected to an upper oil chamber located at the upper part of the cylinder body, and a bypass having a high flow resistance communicates with the upper oil chamber, and A small diameter cylinder is integrally provided at the lower part of the cylinder body and extends in the axial direction of the main body, and the oil passage is formed in the small diameter cylinder, and the oil passage is formed in the small diameter cylinder. a valve chamber for accommodating the valve device therein; a valve seat formed on an inner end surface of the valve chamber; a hollow cylindrical valve body facing the valve seat; and a hollow cylindrical valve. 1. A quick-filling master cylinder for a vehicle, comprising a valve spring that urges a body toward the valve seat, and wherein the pressure-responsive valve is incorporated into the hollow cylindrical valve body.